Populations and Samples
What does the population of a data set mean?
The entire amount of people in the data set
What is an inference?
a conclusion made by interpreting data
What are the three measures of center that can be used to compare data sets?
Mean, Median, Mode
What is a sample of a population
a part of the population
What is a valid inference?
an inference that is very likely to be true about the population
True or False: A box and whisker plot that has a larger box has a smaller IQR and variability?
False
What is sample bias?
A sample that does not give everyone in the population a chance to participate and is not random.
Three fisherman collected data on three different samples of 200 fish out of a catch of 1,000 fish. Sally says that about 500 bluegill are caught for every 1,000 fish. Is this a valid inference?
No
What does the MAD of a data set represent?
The choir teacher at Hillsdale Junior High wants to determine whether the 56 members of the 7th grade choir want to watch a movie or go on a field trip as a reward for the day after their winter concert. What is a representative sample of the population?
Answers vary
If there is a survey of 300 students and 51 out of 60 voted yes, how many people in total would be expected to vote yes?
255 people
What does the IQR represent
The range of the middle 50% of a data set
True or False: A random sample tends to be a representative sample?
True
Sally says that out of 400 people, 300 people would prefer to watch movies in the theater based on the sample data that 30 out of 100 people prefer to watch movies in theaters. Is this a valid inference?
No
If a data set has any type of outlier, what measure of center would most likely be used?
Median